1) Field of the Invention
This invention relates generally to fabrication of magnetoresistive (MR) heads and more particularly to the fabrication and structure of write heads for magnetoresistive (MR) head and more particularly to the fabrication of a write head using a stitched structure/process and a sunken share pole.
2) Description of the Prior Art
As the magnetic disk drive technology advances, the write gap widths must be reduced. Several processes have been developed to reduce write head size and improve manufacturing processes. The stitched head and partial pole trim processes are processes where the write poles are formed in separate deposition steps.
A challenge to producing narrower write gap widths is to use thinner upper pole layers with the partial pole trim processes.
The importance of overcoming the various deficiencies noted above is evidenced by the extensive technological development directed to the subject, as documented by the relevant patent and technical literature. The closest and apparently more relevant technical developments in the patent literature can be gleaned by considering U.S. Pat. No. 5,875,080 (Seagle) that discloses a write head process with a pole trim step and a process for forming a second set of coils over the second pole.
U.S. Pat. No. 5,935,644 (Heim et al.) shows a zero throat height of a write head by recessing the first insulation layer within the first pole piece.
U.S. Pat. No. 4,875,997 (Wada et al.) shows a grooved substrate where the coils are formed over the groove for a magnetic head.
However, these further improvement is required.
It is an object of the present invention to provide a structure and method for fabricating a write head which can over come the high aspect ratio limitations of photographic techniques for defining the upper pole (P3).
It is an object of the present invention to provide a structure and a method for write head that has a sunken shared pole (S1 and P1) that has a reduce thickness that reduces the aspect ratio.
It is an object of the present invention to provide a method for fabricating a write head that uses chemical-mechanical polish steps to planarize dielectric layers.
To accomplish the above objectives, the present invention provides a structure and a method of manufacturing a write head having a sunken share pole which is characterized as follows. The method includes forming a bottom coil dielectric layer over the first half shared pole. Coils are formed over the bottom coil dielectric layer. Next, second half shared poles (P1) are formed over the first half shared pole (S2). We form a top coil dielectric layer over the structure. In a key step, we chemical-mechanical polish the top coil dielectric layer. A write gap layer (WG) is formed over the front second half shared pole and the top coil dielectric layer over the coils. An upper pole (P3) and hard mask are formed over the write gap layer. We etch the write gap layer and the second half shared pole (P1) using the upper pole as an etch mask to remove a portion of the second half shared pole (P1) adjacent to the write gap layer thereby forming a partially trimmed pole.
Additional objects and advantages of the invention will be set forth in the description that follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of instrumentalities and combinations particularly pointed out in the append claims.